Field of the Invention
The present invention relates to a sheet conveyance apparatus which conveys sheets.
Description of the Related Art
Sheet conveyance apparatuses which convey sheets in image forming apparatuses include apparatuses which perform skew-feed correction according to a side registration method with respect to sheets. In such sheet conveyance apparatuses, a sheet is shifted towards the side of a reference member disposed at the side of a sheet conveyance path by an oblique-feed roller, and a side edge of the sheet is caused to abut against the reference member to thereby correct an inclination of the sheet. For example, in Japanese Patent Application Laid-Open No. H11-189355, a sheet alignment apparatus is described that performs skew-feed correction by causing the side edge of a sheet to abut against a reference guide by means of a plurality of rollers arranged along a sheet conveyance path.
In Japanese Patent Application Laid-Open No. 2008-50082 a sheet conveyance apparatus is described that employs a method that temporarily decelerates the driving speed of an oblique-feed roller when a sheet butts against a reference side plate, and accelerates the driving speed of the oblique-feed roller after the sheet butts against the reference side plate. According to this configuration, it is attempted to reduce damage to a sheet caused by an impact between the sheet and the reference side plate by decelerating the oblique-feed roller, and to secure productivity by accelerating the driving speed of the oblique-feed roller thereafter.
However, when adopting a configuration that accelerates the driving speed of an oblique-feed roller during the course of an operation that conveys a sheet as in the sheet conveyance apparatus described in Japanese Patent Application Laid-Open No. 2008-50082, in some cases turning of the sheet occurs after the sheet is butted against the reference side plate. In such a case, the accuracy of skew-feed correction is reduced by the turning of the sheet, and there is a concern that the sheet will collide with the edge of the reference side plate and be damaged.